Merge pull request #1574 from fluent/tail-ignore-repeated-permission-…

…error

Add ignore_repeated_permission_error

lib/fluent/plugin/in_tail.rb

@@ -28,6 +28,7 @@ def initialize
       super
       @paths = []
       @tails = {}
+      @ignore_list = []
     end
 
     desc 'The paths to read. Multiple paths can be specified, separated by comma.'
@@ -62,6 +63,8 @@ def initialize
     config_param :limit_recently_modified, :time, default: nil
     desc 'Enable the option to skip the refresh of watching list on startup.'
     config_param :skip_refresh_on_startup, :bool, default: false
+    desc 'Ignore repeated permission error logs'
+    config_param :ignore_repeated_permission_error, :bool, default: false
 
     attr_reader :paths
 
@@ -166,7 +169,10 @@ def expand_paths
               end
             else
               if is_file
-                log.warn "#{p} unreadable. It is excluded and would be examined next time."
+                unless @ignore_list.include?(path)
+                  log.warn "#{p} unreadable. It is excluded and would be examined next time."
+                  @ignore_list << path if @ignore_repeated_permission_error
+                end
               end
               false
             end

test/plugin/test_in_tail.rb

@@ -50,6 +50,7 @@ def test_configure
     assert_equal 2, d.instance.rotate_wait
     assert_equal "#{TMP_DIR}/tail.pos", d.instance.pos_file
     assert_equal 1000, d.instance.read_lines_limit
+    assert_equal false, d.instance.ignore_repeated_permission_error
   end
 
   def test_configure_encoding